The medicinal benefits of olive oil and olive extracts is widely being recognized. To make olive oil, the olive fruits are ground into a paste. Pressure is applied to the paste to separate the oil from the ground fruit. In addition to providing olive oil, the pressing also releases the water content of the olive fruit, which contains many water soluble phytochemicals. This water is known by a number of names, including “vegetation water, olive juice, and olive waste water”. Interestingly, while olive juice and its disposal can be a problem for the olive oil producer, this olive juice can be a desirable rich source of phenolic compounds, which can have beneficial nutritional properties.
In the past, methods to concentrate the nutritional olive juice involved time consuming incubation, filtration and/or centrifugation, and/or spray drying steps. Another problem is that the usability of dried or liquid olive juice in food or dietary supplements is limited due to the smell, bitterness, and turbidity of the olive juice, as well as the low content of hydroxytyrosol, one of the active polyphenols.
It would therefore be desirable to develop a better method for producing an all-natural, hydroxytyrosol-rich, non-bitter olive juice extract which is efficient and cost-effective.